Results:
Drugs are most often implicated as the etiology in adults. Cold medicines including non-steroidal anti-inflammatory drugs, multi-ingredient cold medications and anti-pyretic medicines are reported to be important inciting causative factors. In our study this group of medication was also the main SJS causative drug totalizing 53% of the patients. The second most important group of medication was the anti-convulsant (15%, including Phenobarbital, n = 5; Carbamazepim, n = 3 and Phenytoin, n = 3). The etiology of SJS in five patients was unknown. HLA class I B analysis showed HLA-B44:03 as the most prevalent allele, with a gene frequency of 19/148 (12.8%) and a carrier frequency of 18/74 (24,3%). There was a significant association between patients with SJS/NET and HLA-B*44:03 (carrier frequency: p = 0.0224, OR = 2.550, gene frequency: p=0.0167, OR = 2.484). Considering all patients with a HLA-B*44:03 allele we could observed that 66.67% had SJS/NET caused by cold medicine and 5.55% caused by anti-convulsant.

Conclusions:
We found that HLA-B*44:03 was significantly associated with SJS/NET and the main causative drug of these diseases was cold medicine.